His "Don't Make Me Think" is still the best UX book I've ever read. Focused, clear and sensible.
And it's entertaining enough to give to other non-technical "stake holders" in your website planning committee. Which means a lot when you're trying to convince them not to make an egregious UI mistake.
My copy of Don't Make Me Think is ragged because of how much I've read, referenced, shared, and noted in it. It's that good.